Hydrogen storage cylinder, machining welding method and machining device

Abstract

The invention discloses a hydrogen storage cylinder, a machining welding method and a machining device.The hydrogen storage cylinder comprises a first half inner container and a second half inner container, the first half inner container is provided with a first welding butt joint end, and the second half inner container is provided with a second welding butt joint end welded to the first welding butt joint end in the axial direction of the hydrogen storage cylinder; the first welding butt-joint end is provided with a first positioning part, the second welding butt-joint end is provided with a second positioning part, and the first positioning part and the second positioning part are matched and clamped, so that the first half liner and the second half liner are relatively fixed in the radial direction and the circumferential direction, and the first welding butt-joint end and the second welding butt-joint end are positioned and welded. The first positioning part and the second positioning part are matched and clamped to form mechanical interlocking, the positioning effect is achieved, meanwhile, the whole contact face of the positioning structure serves as a welding face, the welding contact area can be increased, and therefore the welding strength of the welding seam of the injection molding inner container of the IV type hydrogen storage cylinder is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of plastic inner liners of hydrogen storage cylinders, and in particular to a hydrogen storage cylinder, a processing and welding method, and a processing device. Background Art

[0002] The liner is a key component of Type IV hydrogen storage cylinders, determining their production efficiency and hydrogen safety performance. Currently, domestic and international cylinder manufacturers widely use an injection molding and welding process to produce the liner for small and medium-sized Type IV hydrogen storage cylinders. This process offers high production efficiency, low production costs, excellent liner density, and stable liner dimensions.

[0003] However, the existing injection-molded liner and welding process results in low weld strength, uneven thickness, and uneven external dimensions in Type IV hydrogen storage cylinders due to the narrow, flat weld end faces of the liner. These issues can weaken the welds, compromising the strength of the liner. Furthermore, deformation at the weld seam can affect the strength of the surface fibers, further compromising the overall safety performance of the Type IV hydrogen storage cylinders. Summary of the Invention

[0004] The purpose of the present invention is to provide a hydrogen storage cylinder, a processing and welding method, and a processing device to solve one or more technical problems existing in the prior art and at least provide a beneficial choice or create conditions.

[0005] The technical solutions adopted to solve the above technical problems are: The present invention provides a hydrogen storage cylinder, comprising a first half inner liner and a second half inner liner, wherein the first half inner liner is provided with a first welding butt end, and the second half inner liner is provided with a second welding butt end welded to the first welding butt end along the axial direction of the hydrogen storage cylinder, the first welding butt end is provided with a first positioning portion, and the second welding butt end is provided with a second positioning portion, the first positioning portion and the second positioning portion are matched and engaged, so that the first half inner liner and the second half inner liner are relatively fixed in the radial and circumferential directions, so as to perform position welding on the first welding butt end and the second welding butt end, wherein the contact surfaces between the first positioning portion and the second positioning portion are both welding surfaces.

[0006] The hydrogen storage cylinder of the present invention has the following beneficial effects: The first and second positioning portions mate and engage to form a mechanical interlock. Three-dimensional positioning replaces two-dimensional planar contact, improving both assembly precision and weld contact area. Using the entire contact surface of the positioning structure as the welding surface increases the weld contact area, thereby enhancing weld strength at the injection-molded inner liner of a Type IV hydrogen storage cylinder.

[0007] As a further improvement of the above technical solution, the first positioning portion includes a recessed structure, and the second positioning portion includes a raised structure.

[0008] As a further improvement of the above technical solution, there are multiple protruding structures, and the multiple protruding structures are arranged at the second welding butt end in a ring-shaped manner and at intervals.

[0009] As a further improvement of the above technical solution, the protrusion structure includes a pointed shape, a rectangular shape or a wedge shape.

[0010] As a further improvement of the above technical solution, the second positioning portion is a symmetrical structure.

[0011] As a further improvement of the above technical solution, the multiple raised structures are divided into a first raised block and a second raised block, and the first raised block and the second raised block are arranged at the second welding butt end in an annular staggered manner. The first raised block is extended radially along the second half of the inner liner, and the second raised block is extended tangentially along the outer diameter of the second half of the inner liner.

[0012] As a further improvement of the above technical solution, the first protruding block and the second protruding block are both wedge-shaped.

[0013] As a further improvement to the above technical solution, overflow grooves are provided on the side edges close to the inner sides of the butt joint end faces of the first half inner liner and the second half inner liner.

[0014] The present invention also provides a processing device for producing and processing the hydrogen storage cylinder as described in any one of the above, comprising: A processing assembly, used for processing the first positioning portion and the second positioning portion; Welding components; The clamping assembly includes a base, a first clamping part, a second clamping part and a driving structure. The first clamping part is fixed to the base, and the second clamping part is slidably arranged on the base. The driving structure is used to drive the second clamping part to approach the first clamping part so that the first half inner liner and the second half inner liner are docked.

[0015] The present invention also provides a processing and welding method for producing and processing the hydrogen storage cylinder as described in any one of the above, comprising: Processing a first positioning portion on the first welded butt end of the first half inner liner; Processing a second positioning portion on the second welded butt end of the second half inner liner; Clean the first half of the inner pot and the second half of the inner pot, and dry them for later use after cleaning; heating the first weld butt end and the second weld butt end to a preset temperature; After heating is completed, move the first half of the inner container and the second half of the inner container so that the first positioning portion and the second positioning portion match and engage with each other, and keep the first welding end and the second welding end welded at a preset pressure; Grind the welds. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments; Figure 1 This is a flow chart of an embodiment of a processing welding method provided by the present invention; Figure 2 Schematic diagram of an example of a hydrogen storage cylinder with an unshaped front end surface, wherein A1 is a schematic diagram of the unshaped front end surface of the inner liner; A2 is a schematic diagram of the welding effect of the unshaped front end surface of the inner liner; Figure 3 Schematic diagram of an example of symmetrical tip shaping of the front end face of a hydrogen storage cylinder welded, wherein B1 is a schematic diagram of the symmetrical tip shaping end face of the inner liner; B2 is a schematic diagram of the welding effect of the symmetrical tip shaping end face of the inner liner; Figure 4 This is a schematic diagram of an example of symmetrical rectangular shaping of the front end face of a hydrogen storage cylinder welded, where C1 is a schematic diagram of the symmetrical rectangular shaping end face of the inner liner; C2 is a schematic diagram of the welding effect of the symmetrical rectangular shaping end face of the inner liner; Figure 5 This is a schematic diagram of an example of asymmetric tip shaping of the front end face of a hydrogen storage cylinder, including a schematic diagram of the welding effect of the asymmetric tip shaping end face of D2 and the inner liner; Figure 6 This is a schematic diagram of a cross-section of the front end of a hydrogen storage cylinder welded together; Figure 7 This is a schematic diagram of a cross-section of the front end of a hydrogen storage cylinder welded together; Figure 8 This is a schematic diagram of a cross-section of the front end of a hydrogen storage cylinder welded together; Figure 9 This is a schematic diagram of a cross-section of the front end of a hydrogen storage cylinder welded together; Figure 10 This is a schematic diagram of a cross-section of the front end of a hydrogen storage cylinder welded together; Figure 11 This is a schematic diagram of an example of symmetrical tip shaping of the front end face of a hydrogen storage cylinder. C1 is a schematic diagram of the symmetrical rectangular shaping end face of the inner liner; C2 is a schematic diagram of the welding effect of the symmetrical rectangular shaping end face of the inner liner. DETAILED DESCRIPTION

[0017] This section will describe in detail the specific embodiments of the present invention. The preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the present invention, but it should not be understood as a limitation on the scope of protection of the present invention.

[0018] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0019] In the description of the present invention, if there are words such as "several", it means one or more, and "more" means more than two. Greater than, less than, and exceed are understood as not including the number itself, and above, below, and within are understood as including the number itself.

[0020] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, and connecting should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0021] In the existing technology, the inner liner of type IV hydrogen storage cylinder is mostly manufactured by injection molding combined with welding process. The traditional welding process relies on the flat butt joint method. Figure 2 The weld end face is narrow and requires strict flatness. Due to the lack of effective positioning structures, misalignment and offset are prone to occur during welding, resulting in insufficient effective weld contact area. Uneven heat conduction during welding can easily cause localized deformation, and significant variations in weld thickness distribution ultimately affect the load-bearing capacity and dimensional stability of the welded structure. Weak links in the weld area may lead to the risk of hydrogen permeation, while surface unevenness affects the stress distribution in the fiber reinforcement layer.

[0022] In order to solve the above problems, it was found that the traditional planar welding structure could not meet the high-precision alignment requirements. Planar contact lacks constraints during the assembly process, and a slight angle deviation will cause the effective contact area of ​​the welding area to drop sharply. To solve the above problems, an attempt was made to set a complementary structure on the butt end face to form a mechanical interlock. Figures 1 to 11 The present invention provides a hydrogen storage cylinder, processing and welding method, and processing apparatus, as described below. Three-dimensional positioning replaces two-dimensional planar contact, improving assembly precision and increasing the welding contact area. Using the entire contact surface of the positioning structure as the welding surface increases the welding contact area, thereby improving the weld strength of the injection-molded inner liner of a Type IV hydrogen storage cylinder.

[0023] Therefore, the present application proposes a first half liner 100 and a second half liner 200, wherein the first half liner 100 is provided with a first welding butt end, and the second half liner 200 is provided with a second welding butt end welded to the first welding butt end along the axial direction of the hydrogen storage cylinder, the first welding butt end is provided with a first positioning portion 110, and the second welding butt end is provided with a second positioning portion 210, the first positioning portion 110 and the second positioning portion 210 are matched and engaged, so that the first half liner 100 and the second half liner 200 are relatively fixed in the radial and circumferential directions, so as to positionally weld the first welding butt end and the second welding butt end, wherein the contact surfaces between the first positioning portion 110 and the second positioning portion 210 are both welding surfaces, and the welding surface refers to the three-dimensional surface where the first positioning portion 110 and the second positioning portion 210 contact each other, specifically, the contact uniformity is ensured by surface polishing, and the welding surface covers the contact area of ​​the entire positioning structure. This design can increase the welding contact area, thereby improving the welding strength at the weld of the injection molded liner of the IV type hydrogen storage cylinder.

[0024] The first positioning portion 110 is a recessed structure formed on the butted end surface of the first half liner 100. This recessed structure can be achieved through mechanical stamping or CNC milling, with the depth determined by the material thickness and weld strength requirements. This structure achieves three-dimensional positioning through geometric coordination with the second positioning portion 210.

[0025] The second positioning portion 210 is a raised structure formed on the mating end surface of the second half liner 200. This can be achieved by injection molding or subsequent machining. The raised portion forms an interference fit or clearance fit with the first positioning portion 110. This structure guides the two halves in precise alignment during assembly.

[0026] Specifically, when the first liner half 100 and the second liner half 200 are mated, the second positioning portion 210 engages the first positioning portion 110, creating a geometric constraint that secures the first and second liner halves 100, 200 relative to each other in both the radial and circumferential directions. The weld surface covers the entire contact area of ​​the positioning structure, ensuring uniform welding energy transfer across the contact surface. The interlocking concave and convex structures create a three-dimensional positioning reference, eliminating radial and angular deviations during assembly.

[0027] Compared to existing technologies, traditional flat welding relies on precise operation to ensure accurate alignment. This solution, however, utilizes a three-dimensional positioning structure to achieve automatic positioning and calibration. While existing welding techniques limit the welding area to line contact along the edge of the end face, this solution utilizes the three-dimensional surface of the concave-convex structure to achieve surface contact welding. While existing welding heat sources are concentrated on a single plane, this solution optimizes the heat diffusion path by increasing the surface area of ​​the three-dimensional structure.

[0028] Through the above technical solution, this application effectively improves the structural strength of the welded area and ensures uniform weld thickness distribution. The weld end surface forms a stable three-dimensional positioning reference, ensuring consistent assembly dimensions. The three-dimensional weld surface design optimizes the heat conduction path and reduces the risk of weld deformation. The interlocking structure provides additional mechanical support after welding, enhancing the overall load-bearing capacity. The improved flatness of the weld surface provides a foundation for uniform stress distribution in the fiber winding layer. Reference Figure 6 This application further proposes that the second positioning portion 210 includes a plurality of raised structures, which are arranged in a circular pattern at intervals on the second welded butt end. Accordingly, the first positioning portion 110 includes a plurality of recessed structures, which are arranged in a circular pattern at intervals on the first welded butt end. The plurality of recessed structures are arranged in a one-to-one correspondence with the plurality of raised structures.

[0029] The multiple raised structures refer to independent raised units distributed along the circumference of the mating end face of the second half liner 200. These can be achieved using a lathe, cutter, milling cutter, or friction, with each raised unit forming a localized contact area. An annular spacing arrangement means that the raised units are evenly distributed along the circumference with gaps remaining. The raised structures may be pointed, rectangular, or wedge-shaped.

[0030] Specifically, refer to Figure 3 A pointed tip refers to a geometric shape with an acute angle or tapered structure at the front end. This can be achieved using a triangular protrusion with an angle of 15-60 degrees. During the docking process, the pointed tip preferentially contacts the edge of the first positioning portion 110 to provide initial positioning guidance. When the first liner half 100 and the second liner half 200 are docked, the tip of the pointed tip first engages the first positioning portion 110, eliminating circumferential misalignment through geometric guidance. This solution achieves initial precise positioning through the guiding function of the pointed tip.

[0031] Reference Figure 4 The rectangular shape refers to a cubic form with right-angled boundaries. This can be achieved using a rectangular protrusion whose width matches the gap between the first positioning portion 110. The flat contact surface ensures uniform axial transmission of welding stress. The rectangular positioning portion then forms surface contact with the sidewall of the recessed portion, evenly distributing the axial thermal stress generated during welding across the rectangular contact surface and preventing localized stress concentration that can lead to welding deformation. The rectangular structure provides a stable contact support surface, increasing welding strength while preventing end face misalignment.

[0032] The wedge shape is a trapezoidal structure with inclined sidewalls, specifically implemented using beveled protrusions with an inclination angle of 5-30 degrees. The self-locking effect of the bevel creates a radial restraining force during the thermal expansion of welding. The beveled surface of the wedge-shaped positioning portion forms an interference fit with the recessed portion. Under high-temperature welding conditions, the radial force generated by the thermal expansion of the metal material is converted into axial compression by the beveled structure, effectively suppressing structural displacement during welding. The wedge-shaped structure also provides additional dynamic restraint. The combined effect of these three factors ensures that the weld end face maintains a stable geometric shape under high-temperature and high-pressure conditions.

[0033] Specifically, during the welding process, when the multiple protruding structures of the second half of the inner liner 200 are matched one by one with the multiple recessed structures of the first half of the inner liner 100, each protruding structure is independently embedded in the corresponding recessed portion to form a discrete positioning contact. The annular spacing layout enables the welding surface to form equally spaced positioning points in the circumferential direction, and the concentricity control of the two halves of the liner is achieved through multi-point constraints. When the welding heat source acts, the spacing area between the protruding structures allows the molten material to fill into the gap, avoiding excessive heat concentration in the molten pool caused by the continuous annular structure. Discrete contact disperses the welding stress to multiple local areas, reducing the risk of deformation caused by stress concentration at a single contact point, and at the same time, the weld thickness tends to be uniform through the replenishment of molten material in the spacing area.

[0034] Compared with existing technologies that use continuous annular protrusions or single protrusions for positioning, the heat of the molten pool concentrates in the annular area during welding, leading to localized overheating of the weld. The continuous contact surface also hinders the flow of molten material, which can easily lead to uneven thickness. This solution uses a discrete protrusion structure design. While retaining the annular positioning function, it utilizes gap space to optimize molten material distribution. It also disperses welding stress through multiple contact points, improving weld quality.

[0035] Through the above technical solution, this application achieves an improvement in the positioning accuracy of the welding end face, solves the stress concentration problem caused by the single structure, and makes the welding molten pool evenly fill the circumferential gap, ultimately forming a weld structure with consistent thickness, thereby ensuring the mechanical properties and sealing reliability of the gas cylinder liner.

[0036] Reference Figure 8 The present application further proposes that the raised structure be divided into a first raised block and a second raised block, the first raised block and the second raised block being alternately arranged at the second welded butt end, the first raised block extending radially along the second half of the inner liner 200, and the second raised block extending tangentially along the outer diameter of the second half of the inner liner 200. A corresponding recessed structure is provided at the first welded butt end.

[0037] The first protruding block refers to a protruding structure extending in the diameter direction on the end face of the second half inner liner 200, which can be implemented in a wedge shape, or a rectangular or pointed shape, etc. Its length direction is parallel to the axis of the second half inner liner 200, and is used to limit the radial displacement of the welding end face. The second protruding block refers to a protruding structure extending in the circumferential tangent direction on the end face of the second half inner liner 200, which can be implemented in a wedge shape, or a rectangular or pointed shape, etc. Its extension direction is perpendicular to the first protruding block, and is used to resist circumferential shear force. The staggered spacing refers to the alternating arrangement of the first protruding block and the second protruding block in the circumferential direction, which can be implemented in a manner with an interval angle of 10°-200° to form a complementary positioning structure.

[0038] Specifically, when the first liner half 100 and the second liner half 200 are mated, the radially extending features of the first protruding block engage with the corresponding grooves of the first positioning portion 110, preventing radial misalignment during welding. Simultaneously, the tangentially extending features of the second protruding block form multi-angle contact surfaces with the first positioning portion 110, inhibiting circumferential displacement of the weld end face. The staggered arrangement of the two protruding blocks creates staggered positioning support on the weld surface. The first protruding block evenly distributes support force radially, while the second protruding block disperses circumferential stress tangentially, thereby maintaining a uniform end-face gap during the weld fusion process.

[0039] Compared with the existing technology, conventional technology only uses a single-direction positioning structure, such as an annular boss or evenly spaced rectangular protrusions. Such structures are prone to local deformation when subjected to composite directional stress. However, this solution forms constraints on the welding end face in the orthogonal direction through the combined layout of radial and tangential protrusions, and the staggered support structure formed by the staggered arrangement can avoid the generation of stress concentration areas. This application solves the problem of dislocation deformation of the welding end face caused by insufficient unidirectional positioning, so that the welding pool maintains a uniform thickness distribution during the solidification process. At the same time, the shear resistance and torsional strength of the welded joint are improved through multi-dimensional positioning constraints, thereby improving the structural stability of the welded liner.

[0040] The present application further proposes that the first protruding block and the second protruding block of the hydrogen storage cylinder are both wedge-shaped structures.

[0041] The wedge shape can be formed by machining and cutting, and the difference in its bevel can be controlled within the range of 0.5-3 mm. Specifically, the first protruding block extends radially and the second protruding block extends tangentially to form a spatially staggered fit. When the welding end faces are butted, the longer bevel of the first protruding block preferentially contacts the first positioning portion 110 to form an initial guide, while the tangential bevel of the second protruding block gradually generates a lateral extrusion force during the axial advancement process. By actively adjusting the stress concentration point in the contact area through the difference in bevel geometry, the residual stress generated by material shrinkage during welding is dispersed to different bevel areas, thereby maintaining the stability of the closed state of the weld surface.

[0042] In other embodiments, referring to Figure 9 The present application further proposes that the hydrogen storage cylinder includes a first half inner liner 100 and a second half inner liner 200 welded together, the butt joint end surface of the first half inner liner 100 is provided with a first positioning portion 110, and the butt joint end surface of the second half inner liner 200 is provided with a second positioning portion 210, and the second positioning portion 210 is an annular protrusion.

[0043] Among them, the annular protrusion refers to a protruding structure that extends continuously along the circumference of the mating end face of the second half inner liner 200, which can be realized by turning or injection molding. This structure can form a complete closed contact surface and provide uniform support force for the welding process.

[0044] The welding surface refers to the contact area where the first positioning portion 110 and the annular protrusion match each other, which can be achieved by laser welding or friction welding. The annular contact surface can eliminate deformation caused by local stress concentration during the welding process.

[0045] Specifically, the annular projection and first positioning portion 110 form a circumferentially continuous engagement structure when joined. During welding, heat is evenly transferred along the annular contact surface, preventing localized overheating and material softening or differential shrinkage. The symmetry of the annular structure ensures that the two halves remain coaxially aligned under axial pressure, maintaining the smoothness of the outer surface profile of the inner liner after welding. The weld pool forms a closed weld within the annular region, with its thickness consistency achieved by the annular projection's restraining effect on the molten material.

[0046] Compared to existing technologies, traditional discretely distributed protrusions only provide support in localized areas, resulting in limited effective contact area and uneven heat distribution. The continuous contact surface formed by the annular protrusions not only expands the weld area but also creates a uniform circumferential stress distribution, eliminating the risk of localized deformation caused by discrete support points. Furthermore, flash generated during welding with the annular structure is evenly discharged along the circumference, preventing dimensional deviations caused by localized accumulation.

[0047] Through the above technical solution, this application achieves a significant increase in the contact area of ​​the welding surface and enhances the shear strength of the weld area; the symmetrical characteristics of the annular structure make the welding heat-affected zone evenly distributed, ensuring the consistency of the welding thickness; the coaxial accuracy of the two half-bladders is improved through the circumferential continuous constraint effect, ensuring that the outer surface size of the inner bladder after welding meets the design requirements.

[0048] The present application further proposes that overflow grooves 120 are provided on the side edges close to the inner sides of the butt joint end surfaces of the first half inner liner 100 and the second half inner liner 200 .

[0049] Among them, reference Figure 11 The overflow groove 120 refers to a groove structure provided along the inner edge of the butt joint end face. Specifically, it can be realized by machining or injection molding, and its cross-sectional shape can be rectangular, trapezoidal, or circular. The groove body is used to contain the molten material overflowing during the welding process, and prevent it from accumulating outside the welding area to form surface protrusions. The side close to the inside refers to the position where the inner edge of the butt joint end face is at a specific distance from the inner wall surface of the gas cylinder. Specifically, it can be determined by calculating the range of the welding heat-affected zone to ensure that the overflow groove 120 is within the range of the welding heat source and does not damage the structural integrity of the inner wall.

[0050] Specifically, when the two half-liners are butt-welded, the heated molten plastic material flows around the butt-welding surface under pressure. The overflow trough 120 provides a preset accommodation space, allowing excess molten material to flow into the trough along the inner side of the welding surface, thereby preventing the material from overflowing to the outer surface of the gas cylinder to form irregular protrusions. In particular, when the butt-welding end surface of the first half liner 100 is provided with a first positioning portion 110, and the butt-welding end surface of the second half liner 200 is provided with a second positioning portion 210, refer to Figure 10 Second positioning portion 210 is an annular protrusion. Overflow material generated during welding is evenly discharged along the circumference and located precisely within overflow trough 120. This design controls the flow path of the molten material through spatial constraints, ensuring uniform material distribution in the weld area and consistent weld cross-sectional dimensions. Furthermore, the symmetrical arrangement of overflow trough 120 creates a continuous, closed receiving channel when the two halves are joined, eliminating localized stress concentration caused by uneven material distribution during welding.

[0051] Compared to existing technologies, traditional welding processes lack an overflow chute 120, allowing molten material to freely overflow and form irregular flash, requiring subsequent grinding and easily causing deformation of the weld surface. This solution, through structural optimization, actively controls material flow during the welding process, avoiding weld dimensional deviations and surface defects caused by improper overflow handling in conventional processes, thereby fundamentally ensuring the geometric accuracy of the weld surface.

[0052] This application effectively solves the problems of weld size deviation and surface unevenness caused by overflow of molten welding material. It avoids deformation of the welding surface by directionally accommodating the overflow material, and eliminates the stress concentration caused by material accumulation, thereby significantly improving the structural stability of the welding part and the pressure safety of the gas cylinder.

[0053] The present application further proposes that the second positioning portion 210 is constructed as a symmetrical structure.

[0054] Among them, reference Figure 4 The symmetrical structure can be implemented using a rectangular, trapezoidal, or equilateral wedge-shaped cross-section, ensuring balanced restraint on both weld surfaces during the butt joint process. When a symmetrical structure is employed, the engaging surfaces on both sides of the second positioning portion 210 extend at the same inclination angle or symmetrical profile, creating a bidirectionally symmetrical stress distribution when the weld end faces meet, eliminating weld surface offset caused by unilateral force.

[0055] Reference Figure 5 The asymmetric structure can be specifically realized by using a single-sided bevel, an unequal-sided wedge or a stepped cross-section, and under specific assembly conditions, the end face processing error can be compensated by the difference in structural morphology. When an asymmetric structure is adopted, the clamping surface on one side of the second positioning part 210 has a larger contact area or a guide bevel at a specific angle, which preferentially contacts the first positioning part 110 during the assembly process, and guides the end face to gradually fit together through the difference in structural morphology, thereby compensating for the end face gap caused by processing errors. These two structural options are adapted according to the positioning accuracy of the welding equipment and the tolerance range of the inner liner end face processing, so that the positioning part can form an effective constraint under conventional manufacturing conditions or complex assembly conditions.

[0056] The present application further proposes a processing device, including a processing assembly, a welding assembly and a clamping assembly. The clamping assembly includes a base, a first clamping part fixed to the base, a second clamping part slidably arranged on the base and a driving structure. The base is provided with a slide rail, the second clamping part is slidably arranged on the slide rail, and the sliding second clamping part can be close to the first clamping part. The driving structure is connected to the second clamping part in a transmission manner. The driving structure is used to drive the second clamping part to approach the first clamping part so that the first half liner 100 and the second half liner 200 are docked. The driving structure includes driving units such as a motor, a cylinder, and an oil cylinder. Linear displacement is achieved between the second clamping part and the base through a guide rail or a ball screw. Specifically, a servo motor can be used to drive the second clamping part to achieve precise movement to ensure that the axes of the two half liner coincide.

[0057] The injection-molded half liner is secured to the fixed structure of a machining assembly. The weld end faces are shaped into a specific configuration using lathes, cutters, milling cutters, friction, and other methods. This removes the polymer oxide layer and, by shaping the weld end faces into a specific shape, increases the weld contact area, thereby improving the weld strength at the weld seam of the injection-molded liner of a Type IV hydrogen storage cylinder. The machining assembly is used to machine the first welded butt end of the first liner half 100 and the second welded butt end of the second liner half 200. Specifically, the first positioning portion 110 and the second positioning portion 210 are formed through machining using lathes, cutters, milling cutters, and other methods.

[0058] The welding assembly refers to a device used to implement end face welding, which can be specifically achieved by using a laser welding head or high-frequency induction welding equipment, directly acting on the matching butt end faces.

[0059] Specifically, during the processing, the processing component first punches or cuts the butt end faces of the two half liner to form a first positioning portion 110 and a second positioning portion 210. Subsequently, the first half liner 100 is fixed on the first clamping portion, and the second half liner 200 is loaded into the second clamping portion. Since the two clamping portions are located in the same straight line, the second clamping portion slides along the base to push the second half liner 200 toward the first half liner 100, so that the second positioning portion 210 is precisely fitted with the first positioning portion 110. The welding assembly welds the end faces after fitting. Since the axes coincide and the end faces are completely fitted, the molten pool is evenly distributed during welding and the weld thickness is consistent.

[0060] Among them, the design standards for the shaping of the welded end face of the injection molded liner are as follows: 1. Shaping must not affect the overall dimensions of the welded liner, including the diameter, thickness, and length of the liner, especially the length of the cylinder; 2. The welding end surface should be provided with a positioning part for welding the two parts of the inner liner, which is used to align the welding end surfaces of the inner liner on both sides when the welding end surface is slightly melted; 3. The shaping design of the welding end surface should increase the welding end surface area as much as possible to enhance the welding strength of the inner shells on both sides.

[0061] In some embodiments, a scale or laser locator may be provided on the base to monitor the displacement of the second clamping portion in real time. The clamping surfaces of the first and second clamping portions may be designed as contoured structures that match the outer contour of the half-bladder to enhance clamping stability.

[0062] Compared with existing technologies, traditional machining devices rely on manual adjustment of the half-bladder position, which can lead to alignment errors and uneven clamping force. This solution, however, eliminates the uncontrollable factors of manual intervention through linear constraints on the base and mechanical positioning of the sliding clamp. Furthermore, the pre-formed concave and convex positioning structure of the machining component further enhances axial alignment accuracy.

[0063] Through the above technical solution, this application solves the problems of low weld strength, uneven thickness, and dimensional deformation caused by misalignment during the welding of injection-molded liner. Mechanical constraints ensure the alignment of the half liner axes, and the complementary engagement of the concave and convex positioning structures achieves precise end-face alignment, making the welding process stable and controllable, ultimately achieving a uniform and dense weld structure.

[0064] The present application further proposes an embodiment of a processing welding method, comprising the following steps: Step S100: processing a first positioning portion 110 on the first welding butt end of the first half inner liner 100; Step S200: processing a second positioning portion 210 on the second welded butt end of the second half inner liner 200; Step S300: Clean the first half of the inner container 100 and the second half of the inner container 200, and dry them for later use after cleaning. Step S400: heating the first welding butt end and the second welding butt end to a preset temperature; Step S500: After heating is completed, the first half inner container 100 and the second half inner container 200 are moved so that the first positioning portion 110 and the second positioning portion 210 are matched and engaged, and the first welding end and the second welding end are welded at a preset pressure; Step S600: selecting whether to grind the weld according to the overflow situation; Specifically, step S100 and step S200 include: fixing the first half of the liner 100 obtained by injection molding on a shaping device, and shaping the welding end surface into a symmetrical pointed shape by means of a lathe, a cutter, a milling cutter, friction, etc. Figure 3 As shown in Figure B1, while removing the polymer oxide layer, the weld end surface is formed into a symmetrical pointed shape. This symmetrical pointed shape is one of the first positioning portions 110. This increases the weld contact area, thereby improving the weld strength at the weld seam of the injection-molded inner liner of the Type IV hydrogen storage cylinder. Similarly, the second positioning portion 210 is formed using the same method. The second positioning portion 210 engages with the first positioning portion 110 to achieve precise alignment before welding.

[0065] Step S300 includes: After shaping, the surfaces of the first and second half liner 100 and 200, as well as the weld surface, are cleaned with water to remove polymer debris and dust. Alcohol is then used to clean the surfaces and weld surface to remove oil, with particular attention paid to the shaped weld end surfaces. After cleaning, the surfaces are dried for later use. This cleaning and drying process improves the cleanliness of the weld interface and reduces the risk of pores and cracks.

[0066] Step S400 includes: fixing the cleaned and dried first half liner 100 and second half liner 200 to the first clamping part and the second clamping part respectively, adjusting the first clamping part and the second clamping part so that the first half liner 100 and the second half liner 200 are relatively horizontal, moving the second clamping part, and matching the two end faces of the first half liner 100 and the second half liner 200 to be engaged.

[0067] Step S500: Heat the welding end surfaces of the first half liner 100 and the second half liner 200 according to the design process. After the heating is completed, maintain the rated pressure for welding. After the welded part cools down to about room temperature, take it out to obtain a complete welded liner. Figure 3 As shown in B2.

[0068] Step S600: Because the welding surface of the injection-molded inner liner of the Type IV hydrogen storage cylinder has been specially shaped, the amount of overflow at the weld is small after welding. However, it is still possible to choose whether to grind the weld according to the situation; Specifically, before welding, the mechanical interlocking of the concave and convex positioning structures eliminates offset between the half-bladder joints, ensuring a perfect fit at the weld interface. A cleaning process removes contaminants from the interface, preventing the formation of pores or inclusions during welding. The sliding mechanism of the clamping assembly achieves uniform flow of the molten material through precise displacement control, resulting in a consistent thickness distribution in the weld zone. Heating parameters are dynamically adjusted based on the material's thermal melting characteristics to optimize the molten pool formation process. Finally, the need for polishing is determined based on the flash shape, minimizing post-processing steps while ensuring dimensional accuracy.

[0069] Compared with the existing technology, the traditional welding process adopts a flat butt joint method, which relies solely on the clamping force of the fixture to control the positioning accuracy, which is prone to axial misalignment and causes uneven weld thickness. This method establishes a physical guide reference through a concave and convex positioning structure, and completes self-centering positioning before welding, so that the welding process does not need to rely on complex external positioning devices. The existing technology lacks an end face pretreatment process, and residual impurities at the welding interface directly affect the fusion quality, while this method significantly improves the interface bonding strength through a cleaning and drying process. In addition, the existing technology generally requires forced grinding of all welds, and this method selectively processes according to the overflow status to avoid excessive processing and damage to the base material. This method improves the overall welding strength of the liner, reduces overflow at the welding site, and improves overall safety.

[0070] The above specifically describes the preferred embodiments of the present invention, but the invention is not limited to the embodiments. Those skilled in the art can make various equivalent modifications or substitutions without violating the spirit of the present invention. These equivalent modifications or substitutions are all included in the scope defined by the claims of this application.

Claims

1. A hydrogen storage cylinder, characterized in that: The hydrogen storage cylinder comprises a first half inner liner and a second half inner liner, wherein the first half inner liner is provided with a first welding butt end, and the second half inner liner is provided with a second welding butt end welded to the first welding butt end along the axial direction of the hydrogen storage cylinder, the first welding butt end is provided with a first positioning portion, and the second welding butt end is provided with a second positioning portion, the first positioning portion and the second positioning portion are matched and engaged, so that the first half inner liner and the second half inner liner are relatively fixed in the radial and circumferential directions, so as to perform position welding on the first welding butt end and the second welding butt end, wherein the contact surfaces between the first positioning portion and the second positioning portion are both welding surfaces.

2. A hydrogen storage cylinder according to claim 1, characterized in that: The first positioning portion includes a concave structure, and the second positioning portion includes a convex structure.

3. A hydrogen storage cylinder according to claim 2, characterized in that: There are multiple protrusion structures, and the multiple protrusion structures are arranged at intervals in a ring shape at the second welding butt end.

4. A hydrogen storage cylinder according to claim 3, characterized in that: The protruding structure includes a pointed shape, a rectangular shape or a wedge shape.

5. A hydrogen storage cylinder according to claim 3, characterized in that: The second positioning portion has a symmetrical structure.

6. A hydrogen storage cylinder according to claim 3, characterized in that: The multiple raised structures are divided into a first raised block and a second raised block. The first raised block and the second raised block are arranged at the second welding butt end in an annular staggered manner. The first raised block is extended radially along the second half of the inner liner, and the second raised block is extended tangentially along the outer diameter of the second half of the inner liner.

7. A hydrogen storage cylinder according to claim 6, characterized in that: The first protruding block and the second protruding block are both wedge-shaped.

8. The hydrogen storage cylinder according to claim 1, characterized in that: An overflow groove is provided on the side edge close to the inner side of the butt joint end surface of the first half inner container and the second half inner container.

9. A processing device, characterized in that: Used for producing and processing the hydrogen storage cylinder according to any one of claims 1 to 8, comprising: A processing assembly, used for processing the first positioning portion and the second positioning portion; Welding components; The clamping assembly includes a base, a first clamping part, a second clamping part and a driving structure. The first clamping part is fixed to the base, and the second clamping part is slidably arranged on the base. The driving structure is used to drive the second clamping part to approach the first clamping part so that the first half inner liner and the second half inner liner are docked.

10. A processing welding method, characterized in that: Used for producing and processing the hydrogen storage cylinder according to any one of claims 1 to 8, comprising: Processing a first positioning portion on the first welded butt end of the first half inner liner; Processing a second positioning portion on the second welded butt end of the second half inner liner; Clean the first half of the inner pot and the second half of the inner pot, and dry them for later use after cleaning; heating the first weld butt end and the second weld butt end to a preset temperature; After heating is completed, move the first half of the inner container and the second half of the inner container so that the first positioning portion and the second positioning portion match and engage with each other, and keep the first welding end and the second welding end welded at a preset pressure; Grind the welds.

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